But the main opposition party, the Movement for Democratic Change (MDC), said Mugabe should think about whether his country, which is in the grips of an economic crisis, would not be better served by his bowing out.

"Robert Mugabe should take time to reflect and say isn't it time for me to pass on the baton," MDC spokesman Obert Gutu told AFP.

Mugabe once quipped that he would rule until he turns 100.

Despite his advanced age and recent speculation over his health, Mugabe has avoided naming a successor, prompting perennial infighting among rival factions in his ruling ZANU-PF party jostling for his post.

Despite his age, he continues to give lengthy speeches in public, but his frailty was laid bare last year when he tripped and fell down steps at a televised ceremony.

He also courted ridicule in September by reading a speech to parliament, apparently unaware that he had delivered the same address a month earlier.

His government is accused of systematic human rights abuses and tipping the country into a severe crisis through a campaign of violent land seizures.

Born on February 21, 1924, Mugabe trained as a teacher and taught in what was then Rhodesia and Ghana before returning home to join the guerrilla war against white minority rule.

He became prime minister on Zimbabwe's independence from Britain in 1980 and then president in 1987.